diff --git a/plutocommandparser/README.md b/plutocommandparser/README.md
index 5869341..d8c1879 100644
--- a/plutocommandparser/README.md
+++ b/plutocommandparser/README.md
@@ -4,9 +4,9 @@ PlutoEngine's command parser.
 
 ## Description 
 
-PlutoCommandParser is an attempt to streamline my previous attempts at command parsers. Its main
-goal is to provide a streamlined and flexible tokenizer, parser and evaluator for a simple 
-user-friendly CLI-like language called `PlutoCmd`.
+PlutoCommandParser is an attempt to streamline my previous attempts at command parsers.
+Its main goal is to provide a modular and flexible tokenizer, parser and evaluator
+for a simple user-friendly CLI-like language called `PlutoCmd`.
 
 ## Goals
 
@@ -26,7 +26,7 @@ never be a Turing-complete language.
 ### Command implementation
 
 Each command has its own *final* class, abstractions over CommandBase are howered allowed. 
-Note the usage of `ConstantExpression` annotation over some interface methods. These 
+Note the usage of the `ConstantExpression` annotation over some interface methods. These 
 annotations **must** be respected - methods must be stateless and deterministic.
 
 ## PlutoCmd language specification
@@ -39,7 +39,7 @@ annotations **must** be respected - methods must be stateless and deterministic.
 
 `prefix` is an optional identifier String to distinguish PlutoCmd commands from other commands.
 
-`command` is an alias for a command, handled by one of the command handlers 
+`command` is an alias for a command, handled by one of the command's handlers 
 
 `argX` is an argument of the invoked command-function, optionally quoted to preserve whitespace.
 
diff --git a/plutocommandparser/src/main/java/cz/tefek/pluto/command/resolver/generic/GenericResolver.java b/plutocommandparser/src/main/java/cz/tefek/pluto/command/resolver/generic/GenericResolver.java
index f86d3ed..28f2c44 100644
--- a/plutocommandparser/src/main/java/cz/tefek/pluto/command/resolver/generic/GenericResolver.java
+++ b/plutocommandparser/src/main/java/cz/tefek/pluto/command/resolver/generic/GenericResolver.java
@@ -19,5 +19,5 @@ public abstract class GenericResolver<R> extends AbstractResolver
     }
 
     @Override
-    public abstract Class<R> getOutputType();
+    public abstract Class<? super R> getOutputType();
 }